Wing flap



June 25, 1940. JOYCE 2,205,479

WING FLAP Filed Aug. 14, 1957 3 Sheets-Sheet 1 727m:- NJorc:

T. N. JOYCE June 25, 1940.

WING FLAP Filed Aug. 14, 1957 3 Sheets-Sheet 2 gvwc/wm 7271/ /1/ Jam:

June 25, 1940.

T. N. JOYCE WING FLAP Filed Aug. 14, 1937' 3 Sheets-Sheet 3 BS ku kwau img M 7ZWP4HVJWc:

Patented June 25, 1940 UNITED STATES WING FLAP Temple N. Joyce, Arnold, Md., assignorto Zip Development Corporation, Baltimore, Md, a corporation of Delaware Application August 14, 1931, Serial No. 159,158

3 Claims. (Cl. 244-42) My invention relates to an airplane construction, and more particularly to a flap construction adapted to change the flow around the surface of an airfoil.

An object of my invention is to obtain a balanclng eflect during the time of lowering the p slot effect between the flap and the airfoil which gives an increased emciency to the action of the flap by producing desirable phenomena in the flow of air back of the main airfoil.

A further object is to decrease the turbulence back of the main airfoil and thereby reduce tail bufleting which is so common in certain flap installations.

With these and other objects in view, which may be incident to my improvements, the invention consists in the parts and combinations to be hereinafter set forth and claimed, with the understanding that the several necessary elements comprising my invention may be varied in construction, proportions and arrangements, without departing from the spirit and scope of the appended claims.

In order to make my invention more clearly understood, I have shown in the accompanying drawings means for carrying the same into practical effect without limiting the improvements in w their useful applications to the particular constructions which, for the purpose of explanation, have been made the subject of illustration.

In the drawings: k

Figure 1 is a top plan view of anairplane equipped with my flap construction;

Fig. 2 is a fragmentary perspective view of the operating mechanism for my wing flaps;

Fig. 3 is a sectional view taken through the rear of a wing showing my flap construction with the flap in the up or closed position;

Fig. 4 is a view similar to Figure 3, showing the flap in the down position;

Fig. 5 is a detail sectional view taken along the line 5--5 of Figure 4, looking in the direction of the arrows;

Fig. 6 is a diagrammatic view showing the geometry of movement of the parts in lowering the flap into operative position.

Referring to the drawings, I have shown an airplane I having a motor 2, fuselage 3, wings l, ailerons 5 mounted above. the wings, and flaps 6 mounted below the wings near the trailing edge.

Each wing 4 has a rear spar I, and is provided with a recess 8 near its trailing edge in which is Aiurther object of my invention is to provide a mounted the flap l. The flap 6 is preferably made of sheet metal and is provided with a lower surface 9 and an upper surface l0 which are attached to U-bracing members Ii. Recesses i2 are formed in the upper surface of the flap in 5 which are located pivots l3 and H. To each of the pivots ii are fastened cranks i5 which are attached at their upper ends to an operating shaft ii. The operating shaft I6 serves as a pivot for the upper ends of the cranks l5. On m the pivots M are mounted links H whose upper ends are pivoted at points I8 in the wing construction.

The hollow shaft I6 is provided with a worm gear i9 which meshes with a worm 2|! afiixed to w a shaft 2! which is journaled at 22 and 23 in the fuselage l. The shaft 2| is operated through meshing beveled gears 24', one of which is rotated by means of an operating handle 25. The operating handle 25 is located near the pilot's 50 seat so that he can, through rotating the handle 25, rotate the hollow shaft is to move the flap into either its operative position, as shown in Figure 3, or a lower position wherein-the flap is extended and eflects the air flow arounda 25 wing.

Each wing 4, at its trailing edge, has a series of horns 26 on which are mounted ailerons 5 which are controlled by rods 2'! connected to suitable control members mounted in the fuse- 9 legs.

When the flap is in its Fig.3 raised position, the lower surface 8 of the flap forms, in effect, a continuation of the rear portion of the associated wing undersurface so that the air will flow smoothly across the wing undersurface. By preference, the flap does not project rearwardly beyond the trailing edge of the wing and is located in the concave recess 8 formed below the wing uppersurface whereby the smooth flowing m lines of the wing uppersurface are not broken It is to be noted that with the flap in the position shown in Figure 4, there is provided a slot between the nose 2. of the flap and the recess 8 45 formed in the lower surface oi. the wing ti. This slot gives a desirable slot and balancing eflfect which is highly desirable and increases not only way of stating this is to say that the flap in all its extended positions has its trailing edge substantially in the locus of perpendiculars to the datum lines for the wing sections which pass through the trailing edges of the wing. 'Ihis type of flap, in combination with the slot eiiect presents advantages in operation and performancewhich exceed in desirable features the operative characteristics'of other types of flap.

The geometry of the operation oi the various parts can be seen from an inspection of Figure 6. Figure 6 illustrates that the nose of the flap opens up a definite slot in its downward movement until it reaches a point at which the nose oi. the flap closes the slot between the nose of the flap and the lower surface of the wing.

While I have shown and described the preferred embodiment of my invention, I wish it to be understood that I do not confine myself to the precise details of construction herein set forth by way of illustration, as it is apparent that many changes and variations may bemade therein, by those skilled in the art, without departing from the spirit of the invention or exceeding the scope of the appended claims.

I claim:

1. A flap construction for an airplane comprising an airi'olLa flap adapted to be extended below the airfoil, th 'trailin'g edges of said flap in all operative positionslying'suhstantially in the locus oi perpendiculars to. the vdatum-lines lor the airfoil sections at the trailing. edge of the airfoil sections, and guide means for the flap for the passage of air over the nose and between the flap and airfoil while theflap is being extended downwardly and closes the slot when the flap is completely lowered.

2. In an airplane, a wing, a flap adapted to be extended below the wing, links connecting the flap to the winglso that when the flap is being 7 which cause the nose of the flap-t0 open up a slot, 

